排序方式: 共有33条查询结果,搜索用时 15 毫秒
21.
22.
很多学生学完高中数学新课程标准教材必修模块二的《立体几何》后,感觉心里不踏实.笔者在教学中编拟了一串小问题,利用这些小问题可以把整个模块二的立体几何知识都串起来,无论在模块二的复习中还是在高三第一轮的复习备考中都不失为一串好题, 相似文献
23.
24.
本文首次报道天山翠雀(Delphinium tianshanium W.T.Wang)的化学成份研究,从中分得五种结晶性单体.根据光谱法配合衍生物制备,确定甲素为德它灵(deltaline)(Ⅰ),乙素为德靠灵(delcorine) (Ⅳ),丙素为β-谷甾醇(β-sitosterol).其余成份尚在研究中. 相似文献
25.
A simple full-state asymptotic trajectory control (FSATC) scheme is proposed
to asymptotically drive full states of a unified chaotic system (UCS) to
arbitrary desired trajectories. The FSATC uses only information, i.e. one
state of the UCS. A sinusoidal wave and two chaotic variables are taken as
illustrative tracking trajectories to verify that using the proposed FSATC
can make full UCS states track desired trajectories with high tracking
accuracy in a finite time. 相似文献
26.
La Shalle's invariant-set-theory based asymptotic synchronization of duffing system with unknown parameters 下载免费PDF全文
A novel La Shalle's invariant set theory (LSIST) based adaptive asymptotic
synchronization (LSISAAS) method is proposed to asymptotically synchronize
Duffing system with unknown parameters which also are considered as system
states. The LSISASS strategy depends on the only information, i.e. one state of
the master system. According to the LSIST, the LSISASS method can
asymptotically synchronize fully the states of the master system and the unknown
system parameters as well. Simulation results also validate that the LSISAAS
approach can obtain asymptotic synchronization. 相似文献
27.
28.
采用氧化钆纳米粒子(GON),研究钆基纳米粒子对X射线和碳离子束的辐射增敏效应。首先,通过透射电镜观察材料粒径,使用DLS检测材料的水合半径及Zeta电位,并用紫外吸收谱证实GON在培养基中稳定性较好;研究发现钆(Gd)浓度为10.0 μg/mL的GON对30 keV/μm碳离子束辐照水溶液产生的羟自由基的增强系数为1.13;GON对A549肺癌细胞和正常MRC-5肺细胞没有明显的毒性,且在人肺癌A549细胞中的摄取量随共培养浓度的增加而增加,在10.0 μg/mL共培养浓度下,细胞摄入Gd的量为0.73 pg/cell;进一步采用克隆存活实验证明,GON的加入对X射线和碳离子辐照A549细胞所产生的损伤具有明显的增强,在10%的细胞存活水平下,GON对A549细胞在X射线及碳离子辐照下的辐射增敏分别达15.5%和10.1%。鉴于钆材料常被用于磁共振成像(MRI),所获得的GON有望作为X射线和碳离子的诊疗一体化材料。 相似文献
30.